.av{
    width: 300px;
    height: 100px;
    border: 1px solid blue;
    margin: auto;
    display: flex;
    font-size: 25px;
    text-align: center;
}
.av *{
    width: 100px;
}
.ls{
    float: left;
}
.js{
    float: right;
}